Back in August, we were introduced to quite possibly the scariest, f--ked up trailer ever. "Goodnight Mommy" is an Austrian horror film about twin boys who suspect the woman who comes back home after face changing cosmetic surgery might not be their mother anymore. If you need a refresher on the trailer — or you just like torturing yourself — you can watch it here.

On Thursday, GQ interviewed the star of the film, Susanne Wuest, who shared some creepy terrifying-AF secrets about the making of the movie.

Wuest trained with two cockroaches for two months — and yes, one of them really did go into her mouth.

She also named them Matilda and Nermal, because why not, right?

They filmed out in the middle of nowhere for three months. Like, we're talking a "Courage the Cowardly Dog" kind of nowhere.

Wuest told GQ she had no internet or cell phone reception. THE HORROR. Even worse, she said, "I had no one — no one — to talk about this whole thing. I think after three weeks, I thought, 'I’m going crazy.'"

Wuest didn't necessarily think the movie was horrifying while she was shooting it, but after actually watching the film, she thought it was "really scary."

She knew what all was going to happen, and it still freaked her out. That means the rest of us are doomed.

West worked a trainer to get herself insanely fit... so she could be tied to a bed.

According to her, you prepare yourself to be tied to a bed by taking "care of your back muscles and your abs. You train a lot." So, we now know there's going to be at least one scene of her character strapped to a bed, presumably trying to break free like Regan from "The Exorcist."

The actors worked without a script, which means all the horror was mostly improvised.

However, a script was eventually written, but the two child actors (Lukas and Elias Schwarz) never saw it.

In fact, Wuest claimed the kids haven't even seen the film yet, saying, "They still don’t know what’s going on."

This sounds reminiscent of Danny Lloyd's situation. He played the little boy in "The Shining" and had no idea he was filming a horror movie until many years later.

Sweet dreams!

"Goodnight Mommy" is out now in theaters.